Related Field
The present disclosure relates to a glass run to be mounted to a window frame of a motor vehicle door, and more particularly relates to a structure with a sealing lip to achieve a high degree of sealing by making close contact with a glass windowpane.
Description of Related Art
In general, if a retractable glass windowpane is mounted to a motor vehicle door, the door includes a window frame for supporting the outer periphery of the windowpane and a glass run mounted to the window frame (see, for example, Japanese Unexamined Patent Publication No. 2001-130265). As shown in FIG. 9, the glass run 100 disclosed in Japanese Unexamined Patent Publication No. 2001-130265 is formed in the shape of a channel including a base 101, an exterior wall 102, and an interior wall 103. The exterior wall 102 is provided with an exterior lip 102a, while the interior wall 103 is provided with an interior lip 103a. The interior wall 103 further includes a highly foamed sponge 104 arranged to face an inner surface of the interior lip 103a. The outer periphery of the windowpane is inserted between the exterior lip 102a and the interior lip 103a, which respectively come into contact with the outer periphery of the windowpane from outside and inside of the cabin, thereby achieving a high degree of sealing.
Depending on the situation, it is sometimes necessary to open a glass window only a little. In that case, the top of the glass windowpane is moved down from the window frame, and only the front and rear edges of the windowpane are supported by the window frame via the glass run. Thus, the windowpane may shake inward or outward (i.e., toward or away from the cabin) more easily than in a situation where the window is fully closed. If exciting force is applied in such a state in the vehicle width direction to the windowpane, for example, when the vehicle door with the windowpane is shut or when the motor vehicle is running on a rough terrain, then the windowpane shakes toward or away from the cabin. As a result, in the glass run disclosed in Japanese Unexamined Patent Publication No. 2001-130265, the interior lip 103a in contact with the windowpane also shakes in the same way. In Japanese Unexamined Patent Publication No. 2001-130265, the highly foamed sponge 104 is arranged to face the interior lip 103a. Thus, a so-called “rattle” to be produced when the interior lip 103a comes into contact with the interior wall 103 would decrease.
Nevertheless, the repulsive force of the highly foamed sponge 104 is so weak that if the windowpane is shaking at too high frequencies, then the highly foamed sponge 104 cannot keep up with the movement of the windowpane (i.e., the movement of the interior lip 103a). As a result, the interior lip 103a and the highly foamed sponge 104 come into, and out of, contact with each other quickly and repeatedly, thus sometimes producing strange noise called “contact noise.” Recently, in some situations (e.g., while a vehicle powered by an electric motor such as a hybrid vehicle or an electric vehicle is running at low speeds), it may be very quiet inside the cabin. In such situations, the driver may find the contact noise so strange that some countermeasure needs to be taken to reduce the noise in one way or another.
One possible method may be increasing the size of the highly foamed sponge 104 in the vehicle width direction. In that case, the highly foamed sponge 104 may be pressed strongly against the interior lip 103a. That is why even if the windowpane is shaking at rather high frequencies, the highly foamed sponge 104 would not come out of contact with the interior lip 103a easily, and therefore, the contact noise could be reduced.
If the highly foamed sponge 104 is pressed against the interior lip 103a too hard, however, the interior lip 103a will come into contact with the windowpane so coercively that the windowpane being moved up or down may have its sliding resistance increased to the point of preventing the user from moving the windowpane up or down when the air temperature is extremely low, for example.
In view of the foregoing background, it is therefore an object of the present disclosure to reduce the rattle or contact noise while keeping the sliding resistance of the windowpane low enough.